Anti-scaling device

ABSTRACT

An anti-scaling device comprises a hollow central body for mounting on a bar and several spike units extending outwardly from the body in different directions. Pairs of spike units are rotatably and preferably detachably mounted on opposite sides of the central body. The device may further comprise serrated webs extending outwardly from the central body between the spike units. The device may also comprise rows of sharp-edged teeth axially aligned along the central body. Alternatively, the spike units may be partially rotatable serrated propellers or may be pivotably rotatably mounted. The device may be moulded from plastic material.

FIELD OF INVENTION

This invention relates to anti-scaling device, particularly rotaryanti-sealing devices which can be positioned on top of fences, walls andgates in order to prevent potential intruders scaling such structures.

DESCRIPTION OF ART

Rotary anti-scaling devices generally comprise metal spike unitsextending from a central mounting bar or vanes of expanded metalprojecting from a central rotary bar. These arrangements are prone toscaling using rope and are of relatively fragile construction.Furthermore they are relatively expensive to produce and areaesthetically unappealing.

Other device consist of two identical halves of plastics materialdesigned to connect together to form unitary spikes and be rotatablymounted on an associated bar.

It is an object of the present invention to provide a more effectiveanti-scaling device of relatively inexpensive construction.

SUMMARY OF THE INVENTION

According to the present invention there is provided an anti-scalingdevice comprising a hollow central body portion for mounting on a barand several spike units extending outwardly from the body portion indifferent directions wherein the spike units are rotatably mounted andpreferably rotatably and detachably mounted on the central body portion.

Preferably there are pairs of spike units extending in a diametricallyopposed relationship from the central body portion. It is convenient tomake the spike unit separately from the body portion and to mount thespike units for rotation about radial axes extending out from the bodyportion. In addition serrated webs can be disposed between the spikeunits. This particular construction makes it virtually impossible for anintruder to grab hold of any part of the device, tamper with or attach arope to it.

The spike unit may have a plurality of generally arcuate blade-likeprojections with sharp edges and a sharp tip. These spike units when notin use can be detached and replaced in the event of any damage oraccording to the structure they are securing.

The device with its various components may be made from any tough,resilient material. Ideally, the device is moulded from a plasticsmaterial, particularly a high impact thermoplastic material. The devicewith its various components can come in an assortment of colours fordecorative purposes.

In use the anti-scaling device is rotatable mounted on a bar whichpasses through the hollow central body portion alone the transverseaxis. Preferably a plurality of such anti-scaling devices are rotatablymounted on a bat with the ends of respective central body portionsabutting each other. The bar can then be fixed to an associatedstructure such as a fence, gate or wall etc.

The invention may be understood more readily and various other aspectsand features of the invention may become apparent front consideration ofthe following description.

Embodiments of the present invention will now be described withreference to the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of an anti-scalingdevice constructed in accordance with the invention;

FIG. 2 is an inverted plan view of the first embodiment of theanti-scaling device taken in the direction of arrow A in FIG. 1;

FIG. 3 is a side view of the first embodiment of the anti-scalingdevice;

FIG. 4 is an expanded perspective view illustrating a second embodimentof an anti-scaling device constructed in accordance with the invention;

FIG. 5 is a perspective view of a third embodiment of an anti-scalingdevice constructed in accordance with the invention;

FIG. 6 is an expanded view of the embodiment shown in FIG. 5;

FIG. 7 is a perspective view of three bar-mounted illustrations of afourth embodiment of an anti-scaling device constructed in accordancewith the invention; and

FIG. 8 is an expanded view of part of the fourth embodiment shown inFIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, 2 and 3 the first embodiment of the device iscomposed of components moulded from a suitable plastics material andcomprises a hollow central body portion 1 of a generally elongatecylindrical shape with a bore 9 extending along a central transverseaxis 3. Extending radially in a diametrically opposed relationship fromthe central body portion 1 are two pairs of spigots (not shown) uponwhich separate spike units 5 are detachably and rotatably mounted. Eachspike unit 5 has a central boss portion 21 composed of spaced apart webs22 which taper inwardly to an apex 23. Surrounding the central portion21 there are four arcuate blades 24 with knife-like sharp edges 25 and asharp tip 26. Each unit 5 has a hollow base collar 35 which fits ontoone of the spigots 20. Conveniently the collar 35 may have an internalrib which snap-fits into a groove in the spigot 20 so as to retain theunits 5 on the spigot 20 yet allow for rotation thereabout. Alsoextending radially in a diametrically opposed relationship from thecentral body portion are two pairs of serrated webs 7 having sharp edges11 and points 13, these webs extend along axes displaced 45° from thespigot axes (for clarity, only two webs are illustrated in FIG. 1).

FIG. 4 shows the second embodiment of the device. Like the firstembodiment this embodiment comprises a central body portion 1 with bore9 and diametrically opposed spike units 5 (of which only one is shown).Spigots 20 detachably and rotatably mount the spike units 5 to thecentral body 1. Four axially aligned rows of sharp-edged teeth 15 arepositioned along the central body.

FIGS. 5 and 6 show the third embodiment. The central body portion 1 isformed from two identical halves 17, 19. When assembled (FIG. 5) the twohalves 17, 19 form two radially extending and diametrically opposedsheath units 27. These sheath units 27 each comprise a radialdagger-like serrated blade 29, two diametrically-opposed axially aligneddagger-like serrated blades 31 and two externally serrated tangentialsheaths 33. The sheaths 33 each hold a serrated two-bladed propeller 37rotatably mounted analogous to the spike units 5 of the previousembodiments. The sheaths 33 allow the propellers 37 to partially rotatebackwards and forwards as indicated by the arrows 39.

FIGS. 7 and 8 illustrate the fourth embodiment. In FIG. 7 three centralbody portions 1 are rotatably mounted on a bar 40. Two spike units 5 aremounted on each central body portion 1 although only one is fullyillustrated. The lower spike unit stem 41 represents the second spikeunit in each case. As can be seen the two spike units are diametricallyopposed. In another embodiment based on this fourth embodiment fourdiametrically opposed spike units pet central body portion are presentanalogous to the first and second embodiments described above. As can beseen from FIG. 8 in this fourth embodiment each spike unit 5 comprises astem portion 43 and a cap portion 45. The stem portion 43 is attached tothe central body and extends radially outwards to a moulded retentioncup 47 which surrounds a radial pole 49 on which a moulded sphere 51 ismounted. Three serrated protrusions 53 extend radially from theretention cup 47. The cap portion 45 is covered in radially extendingserrated protrusions 55 and sits on the moulded sphere 51 to pivot androtate as a ball joint as illustrated by the arrows 57. A moulded springis disposed on the pole 49 to centre the cap portion 45 generally aswell as after tampering.

Although the present invention has been described with reference toseveral embodiments, it is apparent that the present invention is notlimited to the aforesaid embodiments, but various modifications can beattained without departing from its scope.

1. An anti-scaling device comprising a hollow central body portionmounted on a bar for rotation around a transverse axis, said bar passingthrough the hollow central body portion along said transverse axis,several spigots or poles extending outwardly from the body portion indifferent directions and spike units each mounted on a said spigot orpole for rotation around axes non-congruent with the transverse axis. 2.An anti-scaling device according to claim 1, wherein the spike units aredetachably mounted on said spigots or poles.
 3. An anti-scaling deviceaccording to claim 1, wherein there are pairs of spike units disposed ina diametrically opposed relationship relative to the central bodyportion.
 4. An anti-scaling device according to claim 1, wherein thecentral body portion has spigots for mounting the spike units.
 5. Ananti-scaling device according to claim 1 further comprising serratedwebs extending outwardly from the central body portion between the spikeunits.
 6. An anti-scaling device according to claim 5, wherein theserrated webs extend along radial axes displaced 45° from the radialaxes of the spike units.
 7. An anti-scaling device according to claim 1,wherein rows of sharp-edged teeth are axially aligned along the centralbody portion.
 8. An anti-scaling device according to claim 1, whereinthe spike units are in the form of partially rotatable serratedpropellers.
 9. An anti-scaling device according to claim 1, wherein thespike units are pivotably mounted.
 10. An anti-scaling device accordingto claim 1, wherein the device is moulded from a plastics material. 11.An anti-scaling device comprising a central body portion mounted on abar for rotation around a transverse axis, said bar passing through thehollow central body portion along said transverse axis, a plurality ofsheaths extending in different directions from the central body portionand a two bladed propeller projecting from and rotatable mounted in eachsheath to rock backwards and forwards.